FIELD OF THE INVENTION
The invention relates to a device for controlling an electromechanical actuator which has an actuating element and an actuating drive. The actuating drive has a moveable armature plate and an electromagnet with a core and a coil. A controller is provided. The control variable of the controller is the current through the coil and its actuating variable is a voltage which is applied to the coil. The invention relates, in particular, to an actuator for controlling an internal combustion engine.
A prior art actuator of this type with an actuating element and an actuating drive is described, for instance, in U.S. Pat. No. 5,053,911 (European publication EP 0 400 389 A2). There, the actuating drive comprises an electromagnet with a core and with a coil. The electromagnet is disposed in a housing. An armature plate is arranged moveably relative to the first electromagnet and is prestressed into a predetermined position of rest by a spring. In order to bring the armature plate out of its position of rest into bearing contact with the first electromagnet, the coil is energized with a pickup current (attraction current). The pickup current generates an electromagnetic force which pulls the armature plate onto the electromagnet counter to a force generated by the spring. The actuator is assigned a two-state controller with hysteresis, the control variable of which is the current through the coil and the actuating variable of which is a pulse-shaped voltage signal which is applied to the coil.